1. Field of the Invention
The present invention pertains to apparatus and methods for use in calibrating systems operated, at least in part, by fluid pressure. More particularly, the present invention relates to techniques for calibrating environment control systems. As used herein, "environment control systems" is intended to include without limitation all types of systems for affecting the environment at a locale, such as systems which might variously be referred to as heating-ventilating-air conditioning (HVAC) systems, climate control systems, air supply systems, heating and/or cooling systems, temperature control systems, humidity control systems, etc., and is not limited to any particular type of system. Also as used herein, the term "calibrate" is used in the broad sense, to include without limitation the determination of operating conditions, the adjustment of operating conditions, the monitoring of operating conditions or the observation of current circumstances, and the like.
2. Description of Prior Art
Typical current environment control systems, such as for use in controlling the temperature in a structure, for example, include apparatus for circulating air relative to the locale and apparatus for providing heated air and/or cooled air to the locale. A thermostat is situated within the locale to monitor temperature and to serve as a control device for actuating components of the system which affect the rate of air supply, heat and cooling, for example. Such components are generally remote from the thermostat so that some means of communication between the thermostat and the components to be controlled by the thermostat must be provided. But the thermostat and the components controlled by the thermostat must be calibrated, the thermostat being calibrated to provide the necessary communication signals to the components at specific temperatures, and the components to actuate in response to specific communication signals.
A common mode of communication between the thermostat and other system components, particularly in larger structures, is by way of a fluid pressure system, and particularly a pneumatic system. A fluid pressure control line connects the thermostat with the components to be actuated. The thermostat serves as a regulator, and must be calibrated to provide to the control line from a fluid pressure source predetermined pressures corresponding to particular temperatures. The components to be actuated must be calibrated to respond to fluid pressure regulated by the thermostat to actuate at predetermined pressure and, therefore, predetermined temperatures.
Currently, it is known to calibrate such a fluid pressure control system by an operator first calibrating the thermostat, and then moving to the vicinity of the components to be calibrated. There, knowing the temperature of the thermostat, the operator observes the condition of the components to be calibrated, for example. The operator can return to the thermostat to change the regulator setting, then proceed again to the components to be actuated to observe their condition again. When the thermostat is at a setting at which actuation of a component is to occur, the operator may adjust the component to just be triggered, assuming that the temperature at the thermostat has remained constant while the operator has moved between locations. With several components to be calibrated for each thermostat, and particularly to actuate at different temperatures, calibration of such a system may be extremely time consuming, inconvenient and tedious.
It is desirable, and economically advantageous, to provide a technique for relatively rapid calibration of environment control systems whereby the operator may complete calibrations of the components to be actuated by the thermostat at the components without returning to the thermostat to alter its setting, for example. Thereafter, the thermostat may be calibrated without return to the calibrated components. Such a technique would preferably include the capability of so calibrating several components for actuation at different temperatures, and even calibrating individual components to change status at two or more temperatures for each such component, or to change continuously with temperature.